The following invention relates to an exercise method and device and more particularly, an exercise method and device for helping to strengthen the abdominal muscles.
Abdominal exercises can be difficult to perform in a way that maximizes the desired effect of strengthening these muscles without causing injury and without involving other muscle groups which may detract from the effectiveness of the exercise. Many abdominal exercises, such as crunches, are done by isometrically contracting the abdominal muscles. For an isometric contraction, static equilibrium (i.e., the lack of motion) during the exercise is achieved by co-contraction of the abdominal muscles (rectus abdominis, internal obliques and external obliques) and the muscles of the lower back. However, stress on the lower back is increased when muscles surrounding the spine contract. Biomechanical stress associated with low-back injury is primarily the result of compressive forces on the intervertebral discs of the spine. These compressive forces are the result of the effects of gravity acting on the body above the lower back when the body is upright and the forces produced by muscles surrounding the spine to counteract flexion-extension moments. It would be advantageous to eliminate the contraction of the back muscles when the abdominal muscles are exercised.
For many isotonic abdominal exercises, such as leg lifts or sit-ups, the forces that must be generated by the abdominal muscles are determined by the weight of the torso and/or the legs. If the person cannot generate enough force to overcome this weight, the exercise cannot be performed. This is also true for many abdominal exercise machines that employ weights or springs. For many people, the level of exertion required to perform the exercise is too high and can result in stress on the lower back that can, in turn, cause injury. Thus, traditional exercises and devices require postures that are often stressful on the lower back or are too difficult to maintain.
Moreover, the actual exercise of the abdominal muscle is reduced by the natural increase of momentum of the torso and/or legs during a crunch, sit up or leg lift. Controlled uniformity of contraction produces more efficient and effective exercise.
Uniformity of contraction of the upper and lower abdominal muscles throughout their range of motion is enhanced by simultaneously engaging both the upper and lower torso, i.e., bringing the chest toward the legs and the legs toward the chest. The term “crunch” exercise as used herein is intended to refer to this movement. The term “crossover crunch” or “crossover” depicts a crunch in which the user presses one side of the upper torso toward the opposite leg while pressing that leg toward the moving aspect of the torso.